Effective Battery Energy Storage System (BESS) noise suppression starts with understanding how sound generated by inverters, transformers and cooling systems is expected to travel through a site.
Equipment layout, terrain and topography are key influences as to how sound behaves, while project location and nearby sensitive receivers establish the acoustic requirements that need to be achieved.
Where barriers are specified for noise suppression, Wallmark Sales Manager Paul Barker said acoustic engineers undertake modelling to determine required performance type.
“We liken the work of an acoustic engineer to a doctor prescribing a script,” Paul said.
“Our role is that of the pharmacist: to deliver a barrier solution with either absorptive or reflective properties, in accordance with that specification.”
Reflective acoustic barriers
Reflective acoustic barriers are typically used where sound can be redirected away from the area being protected, such as a rural setting with little or no nearby dwellings.
Reflective barriers are designed to interrupt the direct path between a noise source and a receiver.
When sound reaches the barrier, some of the sound energy is reflected from its surface, some may be transmitted through the barrier, and some travels over or around it through diffraction.
For BESS applications, reflective barriers can be constructed from materials including steel and concrete.
Absorptive acoustic barriers
An absorptive noise barrier interrupts the direct sound path while incorporating a sound-absorbing surface.
When sound reaches the barrier, the absorptive material reduces the amount of sound energy reflected back into the site by absorbing and dissipating a proportion of that energy.
This is particularly relevant where multiple hard surfaces can create reflected sound paths, including equipment, structures and opposing barriers.
Absorptive barriers can therefore be used to control both the direct transmission of noise and the reflections created when sound interacts with the barrier surface.
For BESS applications, Wallmark offers a non-combustible cassette-style absorptive system incorporating glass wool absorptive material, with an NRC rating of up to 1.0.
Reflective vs absorptive BESS noise barriers
Reflective barrier Absorptive barrier
Primary function Blocks the direct sound path Blocks the direct sound path and reduces reflected sound
What happens at the surface? A proportion of sound is reflected A greater proportion of incident sound is absorbed
When is it typically considered? Where direct-path attenuation provides the required acoustic outcome Where reflected sound also needs to be controlled
Wallmark options Steel or concrete Non-combustible cassette-style system
Key acoustic consideration Sound transmission through and diffraction around the barrier Sound transmission and diffraction, plus absorption of incident sound
Once the acoustic requirements are established, they need to be translated into a barrier that can be engineered and constructed for the conditions of the BESS site.
This means considering the specified acoustic performance alongside structural requirements, material selection, foundations, constructability and long-term durability.
“Our job is to take the acoustic specification and turn it into a practical, engineered solution,” Paul said.
“That means delivering the required performance while making sure the barrier can actually be built efficiently and perform over the life of the project.”
Wallmark provides consultation, design, construction and certification of acoustic barrier solutions for BESS and renewable energy projects throughout Australia.
Contact the Wallmark team on (02) 6057 7600 to discuss your BESS noise suppression requirements.
